scholarly journals THE LIFE HISTORY, DEVELOPMENTAL STAGES, AND TAXONOMIC RELATIONS OF THE DIGENETIC TREMATODELASIOTOCUS MINUTUS(MANTER, 1931) THOMAS, l959

1981 ◽  
Vol 160 (1) ◽  
pp. 146-154 ◽  
Author(s):  
HORACE W. STUNKARD
Keyword(s):  
Life History ◽  
Developmental Stages ◽  
Taxonomic Relations

The cells of Nephromyces: developmental stages of a single life cycle

1983 ◽  
Vol 61 (12) ◽  
pp. 3230-3239 ◽  
Author(s):  
Mary Beth Saffo ◽  
Rebecca Nelson
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Developmental Stages ◽  
Cell Types ◽  
Infective Stage ◽  
Microbial Infection ◽  
Microbial Cells ◽  
Life History Stages ◽  
Single Organism ◽  
Taxonomic Relations

Nephromyces Giard is a diverse collection of funguslike microbial cells, endosymbiotic in the ductless renal sac of molgulid ascidian tunicates (phylum Chordata). Though Giard considered Nephromyces a Chytridiomycete, the taxonomic affinities of these peculiar cells remain uncertain. In Molgula manhattensis DeKay, at least seven Nephromyces cell types can be distinguished. Despite their diverse appearance, these cell types are not separate taxa, but instead are separate life-history stages of a single organism. Developmental roles for these life-history stages are discussed, as are the possible taxonomic relations of Nephromyces. A new Nephromyces cell, a motile but nonflagellated infective stage, is described. The experiments reported here confirm earlier suggestions that the molgulid renal sac is not merely the site of an occasional or random microbial infection. Instead, this organ is the locus of an exclusive, presumably coevolved, association between two taxa: Nephromyces and the tunicate family Molgulidae.

BIOLOGY OF TACHINAEPHAGUS ZEALANDICUS (HYMENOPTERA: ENCYRTIDAE), PARASITOID OF SYNANTHROPIC DIPTERA

1974 ◽  
Vol 106 (8) ◽  
pp. 785-800 ◽  
Author(s):  
G. S. Olton ◽  
E. F. Legner
Keyword(s):  
Life History ◽  
Developmental Stages ◽  
Average Length ◽  
Host Density ◽  
Adult Emergence ◽  
Reproductive Period ◽  
Laboratory Studies ◽  
Pupal Parasitoid ◽  
History Of ◽  
Parasitoid Development

AbstractThe synonymy, distribution, host range, and life history of the gregarious larval–pupal parasitoid Tachinaephagus zealandicus Ashmead, is discussed. Laboratory studies of its biology were conducted at 25° ± 2 °C using Musca domestica L. as host. Its developmental stages are described. Under laboratory conditions its life cycle lasted 23–27 days. Parasitoid development accelerated with higher average densities per host. Single standardized hosts produced 3–18 adult parasitoids. Mated females provided with hosts lived 50.4–67.2 h. The average length of the reproductive period and number of hosts parasitized were independent of host density; however, the average number of eggs deposited per host increased at lower host densities. Adult emergence displayed circadian rhythmicity independent of photoperiod over 3+ days.

Language use, not language, is what develops in childhood and adolescence

2006 ◽  
Vol 29 (3) ◽  
pp. 280-281 ◽  
Author(s):  
Derek Bickerton
Keyword(s):  
Life History ◽  
Language Acquisition ◽  
Language Use ◽  
Developmental Stages ◽  
Language Evolution ◽  
Childhood And Adolescence ◽  
Life History Stages ◽  
Acquisition Period ◽  
Causative Factors

That both language and novel life-history stages are unique to humans is an interesting datum. But failure to distinguish between language and language use results in an exaggeration of the language acquisition period, which in turn vitiates claims that new developmental stages were causative factors in language evolution.

Anuran life history plasticity: Variable practice in determining the end-point of larval development

2010 ◽  
Vol 31 (2) ◽  
pp. 157-167 ◽  
Author(s):  
Patrick Thomas Walsh
Keyword(s):  
Life History ◽  
Developmental Stages ◽  
Life Cycles ◽  
Developmental Phase ◽  
Larval Phase ◽  
End Point ◽  
Anuran Amphibians ◽  
Individual Fitness ◽  
Metamorphic Climax ◽  
Size At Metamorphosis

AbstractPlasticity in the timing of life history events and their impact on individual fitness, particularly the timing of and size at metamorphosis in animals with complex life cycles such as anuran amphibians, has long been of interest to ecologists. For different studies on life history plasticity to be comparable, there must be clearly defined and commonly agreed transition points, but it is unclear how consistently this is being performed in studies using anuran amphibians. In a review of 157 published studies, I found considerable variation in defining the end point of the larval phase. While a slight majority used the emergence of the forelimbs as the conclusion of the larval phase, some used a period within the developmental phase of metamorphic climax and others used the resorption of the tail. Studies included in this review, that assessed the same life history variable at two different developmental stages, reported some differences in results depending on which developmental stage was used. Recent evidence also shows that metamorphic climax is itself a period which can vary with environmental conditions, but, even in studies that included part or all of metamorphic climax in the larval phase, the treatment of individuals during metamorphic climax was not reported. Therefore, I argue that life history studies on anuran amphibians should distinguish the following phases: larval, metamorphic climax, juvenile, adult; that the end of the larval phase is best defined in ecological studies by forelimb emergence and that conditions under which individuals undergo metamorphic climax should be fully described.

Life history of Mysis stenolepis Smith (Crustacea, Mysidacea)

1975 ◽  
Vol 53 (7) ◽  
pp. 942-952 ◽  
Author(s):  
T. Amaratunga ◽  
S. Corey
Keyword(s):  
Young Adults ◽  
Life History ◽  
New Brunswick ◽  
Shallow Water ◽  
Field Study ◽  
Sexual Maturity ◽  
Developmental Stages ◽  
Shallow Waters ◽  
Passamaquoddy Bay ◽  
History Of

A 17-month field study showed that Mysis stenolepis in Passamaquoddy Bay, New Brunswick lives for about 1 year. Young are released in shallow water early in spring and grow rapidly during the summer. In the fall, young adults migrate to deeper water where they reach sexual maturity. Transfer of sperm lakes place during winter in deeper regions of the Bay. soon after which the males die. Females survive and in spring migrate to shallow waters to release young after which they die. Females breed once and carry an average of 157 young per brood. Developmental stages of the postmarsupial young are described and discussed.

Brain size evolution in anurans: a review

2019 ◽  
Vol 69 (3) ◽  
pp. 265-279 ◽  
Author(s):  
Chun Lan Mai ◽  
Wen Bo Liao
Keyword(s):  
Sexual Selection ◽  
Life History ◽  
Life History Traits ◽  
Developmental Stages ◽  
Brain Size ◽  
Ecological Factors ◽  
Brain Regions ◽  
Sperm Length ◽  
Testis Size ◽  
Size Evolution

Abstract Selection pressure is an important force in shaping the evolution of vertebrate brain size among populations within species as well as between species. The evolution of brain size is tightly linked to natural and sexual selection, and life-history traits. In particular, increased environmental stress, intensity of sexual selection, and slower life history usually result in enlarged brains. However, although previous studies have addressed the causes of brain size evolution, no systematic reviews have been conducted to explain brain size in anurans. Here, we review whether brain size evolution supports the cognitive buffer hypothesis (CBH), the expensive tissue hypothesis (ETH), or the developmental cost hypothesis (DCH) by analyzing the intraspecific and/or interspecific patterns in brain size and brain regions (i.e., olfactory nerves, olfactory bulbs, telencephalon, optic tectum, and cerebellum) associated with ecological factors (habitat, diet and predator risk), sexual selection intensity, life-history traits (age at sexual maturity, mean age, longevity, clutch size and egg size, testis size and sperm length), and other energetic organs. Our findings suggest that brain size evolution in anurans supports the CBH, ETH or DCH. We also suggest future directions for studying the relationships between brain size evolution and crypsis (i.e., ordinary mucous glands in the skin), and food alteration in different developmental stages.

scholarly journals V. On the early development of cirripedia

1894 ◽  
Vol 185 ◽  
pp. 119-232 ◽  
Keyword(s):  
Life History ◽  
Early Development ◽  
Developmental Stages ◽  
Short Stay ◽  
Complete Understanding ◽  
Cambridge University ◽  
Modern Methods ◽  
History Of ◽  
Complete Series ◽  
The Subject

During a short stay at Plymouth, in 1889, I was engaged in studying certain points in the anatomy of Cirripedia; finding, however, that a knowledge of the embryology was necessary in order to arrive at a complete understanding of the adult structure, I became wishful to investigate the life-history of some one member of the group. This I had an opportunity of doing at Naples, where I was appointed to occupy the Cambridge University Table at the Zoological Station for a period of six months, subsequently increased to nine. I here succeeded in obtaining a practically complete series of stages of Balanus perforatus , Bruguiere, as well as many stages in other members of the group. Though a number of able observers have occupied themselves with the embryology of Cirripedes, yet, owing to lack of opportunity, and to the difficulty of obtaining complete series of developmental stages, as well' as to the inherent difficulties in the subject, much remained to be done in this line. Willemoes-Suhm alone, with the advantages afforded by his position during the Challenger Expedition, has hitherto obtained a complete series of stages of any one form, but he failed to trace the history of the earlier stages, and in the later, limited himself to the appearance of fresh and spirit specimens, as seen without cutting sections. In fact the method of sections has been little applied to the development of Cirripedes, and not at all to the earlier stages. There is, therefore, little apology needed for an account embracing the results obtained by the employment of some of the more modern methods of embryological study.

Studies on Bathycoelia thalassina (H.-S.) (Hemiptera; Pentatomidae), the cause of premature ripening of cocoa pods in Ghana

1967 ◽  
Vol 57 (2) ◽  
pp. 289-299 ◽  
Author(s):  
N. Lodos
Keyword(s):  
Life History ◽  
Developmental Stages ◽  
Empty Shell ◽  
Distal Half ◽  
Economic Pest

Bathycoelia thalassina (H.-S.), of which the developmental stages and life history are described, is responsible for premature ripening of cocoa pods in Ghana. Experiments conducted at Tafo to determine the nature of the damage to pods showed that the insect feeds directly on the beans, and that beans so attacked turn brown and subsequently die: only the empty shell of the bean remains.The saliva of the insect kills any tissue of the pod that it penetrates and within four days the injured areas cease to grow and become yellow, then brown, and finally black.The symptom most characteristic of damage is the change in colour. The pod may become completely yellow, or yellow in the basal or distal half only (usually the latter) or yellow in spots, depending on the size of the pod, the site of attack, and the duration of feeding at each site.The insect usually attacks pods of the Amazon varieties, 10–17 cm. long. The incision made by the stylets is microscopic, and is covered by a jelly-like substance, and no evident lesions develop on the surface as in damage caused by cocoa mirids or coreids.Damage caused by B. thalassina on young pods resembles cherelle wilt of physiological origin, and the two can be distinguished only by slicing the pods, whereupon the former can be recognised by the presence of injured beans.According to the survey of damage caused by B. thalassina in Ghana, this species seems to be an economic pest on some Amazon and hybrid types of cocoa, whereas Amelonado cocoa usually suffers little.

scholarly journals Impact of CO<sub>2</sub>-driven ocean acidification on invertebrates early life-history – What we know, what we need to know and what we can do

2009 ◽  
Vol 6 (2) ◽  
pp. 3109-3131 ◽  
Author(s):  
S. Dupont ◽  
M. C. Thorndyke
Keyword(s):  
Life History ◽  
Ocean Acidification ◽  
Early Life ◽  
Developmental Stages ◽  
Marine Invertebrates ◽  
Early Life History ◽  
Rate Of Change ◽  
Marine Biodiversity ◽  
Larval Stages ◽  
Long Term Impact

Abstract. As a consequence of increasing atmospheric CO2, the world's oceans are becoming more acidic and the rate of change is increasingly fast. This ocean acidification is expected to have significant physiological, ecological and evolutionary consequences at many organizational levels of marine biodiversity. Alarmingly little is known about the long term impact of predicted pH changes (a decrease of −0.3/−0.4 units for the end of this century) on marine invertebrates in general and their early developmental stages in particular, which are believed to be the more sensitive to environmental disturbances, are essential as unit of selection, recruitment and population maintenance. Ocean acidification (OA) research is in its infancy and although the field is moving forward rapidly, good data are still scarce. Available data reveal contradictory results and apparent paradoxes. In this article, we will review available information both from published sources and work in progress, drawing a general picture of what is currently known, with an emphasis on early life-history larval stages. We will also discuss what we need to know in a field with very limited time resources to obtain data and where there is a high expectation that the scientific community should rapidly be able to provide clear answers that help politicians and the public to take action. We will also provide some suggestions about what can be done to protect and rescue future ecosystems.

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